Dave Mustaine and I are apparently both HUGE leeches from the chain. As proof of that I offer the following:
Name lvl Status %Passed XP Deficit
Oof 155 Failed 21.72% 3,143,499,300
Dave Mustaine 144 Failed 17.48% 3,178,610,038
Yes, folks, that is 3 Billion XP. Aren't you glad you aren't the patron of either one of us?
Ok, enough of that now.

Here's the reason for the post. This wierd looking XP is something you will see occasionally. Anytime either the XP you pass up, or the XP that your vassal passes to you exceeds 4 billion it does strange things to ACStats. On the old chain page, Zataki had put in a fix for it where if you updated after this happened the numbers cleared themselves. This is showing up for the first time on the new chain page. I'm sure Ranger will figure out a fix for this pretty quickly.
In the meantime, if you show some billions of XP in the hole on your quota, don't worry about it. I have to go start earning some XP now before my patron starts yelling at me.